1. Field of the Invention
The present invention relates to a Marx generator.
A Marx generator comprises several capacitor stages which are charged in parallel and discharged in series. Each capacitor stage may be charged at voltages greater than several hundred kilovolts, so that the voltage and the energy available at the output of said generator may respectively reach a few Megavolts and a few tens of kilojoules.
2. Description of the Prior Art
For example, in the French patent application 87 14374 in the name of the Applicant, a Marx generator is described comprising:
a sealed case inside which prevails an atmosphere of a dielectric gas,
a plurality of capacitor stages, of toric shape, arranged in said case coaxially to a common axis and juxtaposed along said axis,
each capacitor stage having a capacitor embedded in a dielectric coating, in the form of a ring, and connected by a plurality of electrodes to two annular terminals coaxial with said axis,
said annular terminals being connected respectively to spark-gap heads housed in the central recess of the capacitor stages, each capacitor stage comprising two spark-gap heads, one of which cooperates with a spark-gap head of the preceding stage and the other cooperates with a spark-gap head of the following stage so as to form each time a pair of associated spark-gap heads.
Such a Marx generator is generally satisfactory in use.
However, in this case, each spark-gap head is connected to a corresponding terminal of the capacitor stage to which said spark-gap head belongs. That leads to the following drawbacks.
In fact, the position of a spark-gap head is adjusted with respect to a theoretical reference (axis) of the capacitor stage to which said spark-gap head belongs. Then, two adjacent stages, each having two semi spark-gaps, are assembled and the respective spark-gap heads are then opposite one another, without it being possible to take action either in so far as the spacing is concerned or their coaxiality.
However, during assembly, the spacing and alignment of the heads may vary randomly if there are mechanical clearances, dimensional spread or clamping stresses, all the more so the higher the number of parts present.
Furthermore, the different dynamic forces brought into play during operation of the generator may cause displacements which modify the position and spacing of the spark-gap heads.
Thus, variations of the triggering characteristics of the Marx generators of the above type are created, which adversely affect their operating reliability.